Denholm, David
Penguin Books, 1979
Buku Teks
Angelino, De Kat
Buku Teks
edited by Patricia Grimshaw, Chris McConville and Ellen McEwen
George Allen and Unwin, 1985
Buku Teks
Mountford, Benjamin, author
Oxford University Press, 2016
eBooks
Finn, Paul, author
Oxford University Press, 1987
Buku Referensi